IC Component Level Failure Induced By Intermetallic Layer Structural Defects of Solder Joint

2002 ◽  
Vol 753 ◽  
Author(s):  
Ming Sun ◽  
Mike Loo ◽  
Lily Zhao

ABSTRACTSolder joint has been widely used in microelectronics industry as an interconnect of Integrated Circuit (IC) chip and Printed Circuit Board (PCB). Frequently, a functional failure of the component on the system is a result of solder joint damage. Eutectic 63Sn/37Pb solder joint mechanical behaviors on Ni/Au plated copper pad and bare copper pad were experimentally investigated to address the effect of pad surface cleanness on the formation of intermetallic compound. The joints with thinner intermetallic compound layer resulted in a poor solder ball shear strength. Microstructural analysis revealed that the oxidations of Ni and Cu during substrate manufacturing contributed to the improper growth of intermetallic compound during assembly and reliability tests. In additions, the experimental results showed that the growth of the intermetallic compound layer were dependent not only on the time and temperature of solder reflow and testing, but also on the cleanness of the pad surfaces and available area for the diffusion of Ni in the case of Ni/Au plated copper pad, Cu in the case of bare copper pad and Sn in the joint area.

2015 ◽  
Vol 27 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Peter K. Bernasko ◽  
Sabuj Mallik ◽  
G. Takyi

Purpose – The purpose of this paper is to study the effect of intermetallic compound (IMC) layer thickness on the shear strength of surface-mount component 1206 chip resistor solder joints. Design/methodology/approach – To evaluate the shear strength and IMC thickness of the 1206 chip resistor solder joints, the test vehicles were conventionally reflowed for 480 seconds at a peak temperature of 240°C at different isothermal ageing times of 100, 200 and 300 hours. A cross-sectional study was conducted on the reflowed and aged 1206 chip resistor solder joints. The shear strength of the solder joints aged at 100, 200 and 300 hours was measured using a shear tester (Dage-4000PXY bond tester). Findings – It was found that the growth of IMC layer thickness increases as the ageing time increases at a constant temperature of 175°C, which resulted in a reduction of solder joint strength due to its brittle nature. It was also found that the shear strength of the reflowed 1206 chip resistor solder joint was higher than the aged joints. Moreover, it was revealed that the shear strength of the 1206 resistor solder joints aged at 100, 200 and 300 hours was influenced by the ageing reaction times. The results also indicate that an increase in ageing time and temperature does not have much influence on the formation and growth of Kirkendall voids. Research limitations/implications – A proper correlation between shear strength and fracture mode is required. Practical implications – The IMC thickness can be used to predict the shear strength of the component/printed circuit board pad solder joint. Originality/value – The shear strength of the 1206 chip resistor solder joint is a function of ageing time and temperature (°C). Therefore, it is vital to consider the shear strength of the surface-mount chip component in high-temperature electronics.


2020 ◽  
Vol 307 ◽  
pp. 26-30
Author(s):  
Azman Jalar ◽  
Maria Abu Bakar ◽  
Mohd. Zulhakimi Ab. Razak ◽  
Norliza Ismail

Evaluating the growth kinetics is one of the most important characteristic in assessing the quality and reliability of metallurgical joining, especially in electronics packaging such as soldering and wire bonding technology. The growth kinetics is normally assessed using Arrhenius equation that involves diffusion activities due to thermally activated process. The well-known factors of thermal and time together with generally accepted growth exponent have been widely used for this assessment. The intermetallic compound layer which is the by-product of metallurgical reaction during soldering process has been exposed to high temperature to accelerate its growth. The cross-section of the joining was observed using optical microscope to quantify the layer of intermetallic compound. Morphological effect and shape factor of the layer have been analysed in complement with the effect of temperature and time on the growth behaviour. Directional growth and irregularities shape of the intermetallic layer show some inconsistency on the selection of growth exponent. The effect of initial size of intermetallic layer must also be considered in this assessment. This study suggests that the morphological effect must be analysed prior to the selection the growth exponent in assessing growth behaviour and kinetics of intermetallic layer in metallurgical joining.


2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Tong An ◽  
Fei Qin

The significant difference between failure modes of lead-containing and lead-free solder joints under drop impact loading remains to be not well understood. In this paper, we propose a feasible finite element approach to model the cracking behavior of solder joints under drop impact loading. In the approach, the intermetallic compound layer/solder bulk interface is modeled by the cohesive zone model, and the crack driving force in the intermetallic compound layer is evaluated by computing the energy release rate. The numerical simulation of a board level package under drop impact loading shows that, for the lead-containing Sn37Pb solder joint, the damage in the vicinity of the intermetallic compound layer initiates earlier and is much greater than that in the lead-free Sn3.5Ag solder joint. This damage relieves the stress in the intermetallic compound layer and reduces the crack driving force in it and consequently alleviates the risk of the intermetallic compound layer fracturing.


Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1155 ◽  
Author(s):  
Yong Keun Kim ◽  
Sun Ig Hong

The effects of interfacial modification in tri-layered Cu/Al/Cu composites by heat treatment on interface stability and crack propagation were investigated. In order to investigate the crack path during the peel test, the intermetallic compound layer with the propagating crack was examined using electron backscatter diffraction (EBSD) analyses. The increase of peel strength from 7.8 to 9.1 N/mm in the tri-layered Cu/Al/Cu composite in the presence of thin discontinuous intermetallic compounds with heat treatment at 200–300 °C was accompanied by the increase of electrical conductivity from 65.3% IACS (International Annealed Copper Standard) to 66.8% IACS. Continuous intermetallic layers consisting of Al2Cu, AlCu, and Al4Cu9 were found in Cu/Al/Cu heat-treated at temperatures above 350 °C and its thickness increased rapidly and reached up to 35.2 μm at 500 °C. The peel strength drastically decreased to 5.75 N/mm after heat treatment at 400 °C, and it gradually increased as the heat treatment temperature was increased to 450 °C (5.91 N/mm) and 500 °C (6.16 N/mm). The increased peel strengths after heat treatment at 450 and 500 °C were accompanied by pronounced serrations of the peel strength–displacement curves. The amplitude of serration increased substantially with increasing annealing temperature from 400 to 500 °C. The major crack along the interface propagated, mostly along the Al2Cu/AlCu boundary with some inclined cracks, propagated through the AlCu and Al4Cu9 intermetallic compound layers. The repetition of crack propagation along the interface and crack deflection through the intermetallic layer as an inclined crack induced the serrated surface on the peeled-off Cu plate, enhancing the interface toughening.


2020 ◽  
Vol 49 (12) ◽  
pp. 2983-2990
Author(s):  
Atiqah Mohd Afdzaluddin ◽  
Maria Abu Bakar

Solder joint is important for providing mechanical support and functionality of electronic packaging. Established solder joint should be able to withstand in device service operation and the environment without significant changes in terms of their microstructural evolution and mechanical properties. This study investigates the effect of the coating element (Sn and Ni) on the joining stability of Sn-0.3Ag-0.7Cu solder joint. The solder joints were exposed to different aging test for 1000 h to observed microstructure and micromechanical properties changes. Microstructural observation by means of intermetallic compound layer thickness due to the aging temperature effect. Joining stability by means of micromechanical changes were studied using nanoindentation approach. It was found that the elastic behavior, reduced modulus, and hardness of Sn-0.3Ag-0.7Cu solder joint has reduced due to aging test. However, the plastic behavior of Sn-0.3Ag-0.7Cu solder joint has increased with the increase of the aging temperature. It is observed that the Ni coating has a significant effect and a more stable solder joint achieved. This can be evidenced from small changes in intermetallic compound layer thickness and micromechanical properties were achieved using Ni coating as compared to Sn coating after subjected to the aging test for 1000 h.


2006 ◽  
Vol 15-17 ◽  
pp. 381-386 ◽  
Author(s):  
I.H. Hwang ◽  
Takehiko Watanabe ◽  
Y. Doi

We tried to join steel to Al-Mg alloy using a resistance spot welding method. The effect of Mg in Al-Mg alloy on the strength and the interfacial microstructure of the joint was investigated. Additionally, the effect of insert metal of commercially pure aluminum, which was put into the bonding interface, on the joint strength was examined. The obtained results were as follows. The cross-tensile strength of a joint between SS400 steel and commercially pure aluminum (SS400/Al) was high and fracture occurred in the aluminum base metal. However, the strength of a joint between SS400 and Al-Mg alloy was remarkably low and less than 30% of that of the SS400/Al joint. An intermetallic compound layer developed so thickly at the bonded interface of the SS400/Al-Mg alloy joint that the joint strength decreased. The intermetallic compound layer developed more thickly as Mg content in the Al-Mg alloy increased. Using insert metal of commercially pure aluminum containing little Mg successfully improved the strength of the SS400/Al-Mg alloy joint and the strength was equivalent to that of the base metal.


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